As described in FRA Report No. FRA/ORD-80/40.11, entitled Alternative Fuels For Medium-Speed Diesel Engines (AFFMSDE) Project, Second Research Phase Final Report, Synthetic Fuels, Alcohol Emulsions, Off-Specification Diesel Fuels and Methanol, the concept of using staged injection, that is multiple injections for utilizing alternative low ignition quality fuels as a substitute for diesel fuel, is discussed. That is, injecting a small portion of the fuel early in the cycle to act as a pilot for the main fuel charge allows the use of fuels having lower cetane numbers than No. 2 diesel fuel. Staged injection is the injection of a fuel charge in two or more stages directly into a diesel engine combustion chamber for the purpose of producing smooth diesel engine combustion and high thermal efficiency while operating on poor quality fuels. The initial or pilot stage is injected early in the compression stroke to allow it sufficient time to undergo pre-flame chemical reactions before injection of the main charge. The main fuel charge is injected near to or at the end of the compression stroke. Combustion of the pilot stage begins before combustion of the main fuel charge starts. The heat released from combustion of the pilot stage aids in the ignition of the main fuel charge. The ignition delay period of the main charge can be controlled by varying the quantity and injection timing of the initial pilot stage. The use of an early injection of a small quantity of fuel to accomplish these results is described in the above report. However, simply injecting a small amount of fuel early, without regard for the fuel-air mixing process, leads to uncertain results. The present invention has found that the initial or pilot stage must be injected in such a manner that the fuel is maintained in the cylinder in a stratified form. The pilot fuel spray should be directed into the combustion chamber at an orientation which will prevent loss of fuels into quench regions or through liner wetting. Further, the orientation and timing must be such that stratification occurs in the combustion chamber producing local fuel/air ratios sufficiently high for combustion of the initial or pilot stage to proceed at a high rate. That is, it has been found that the early injection of pilot or initial stage fuel must (1) have limited mixing with the combustion chamber air during the period of time between the early injection event and the onset of combustion, (2) the pilot injection must not come in contact with cold walls or be trapped in quench regions of the combustion chamber which effectively stops the chemical reaction of fuel and air, (3) the pilot injection is placed along the longitudinal axis of the chamber where the mixing rate is reduced because the air velocity and turbulance of the rotation air in the combustion chamber is a minimum along this longitudinal axis, and (4) the center of the combustion chamber is the preferred location for injected pilot fuel as the temperature in the center of the chamber is higher than at the combustion periphery whereby the injection of the pilot fuel into the hotter cylinder reduces ignition delay.